“…often the soil may be in excellent chemical condition, but compromised from a biological point of view.”
Ieda de Carvalho Mendes is a researcher at Embrapa Cerrados, with a degree in agronomy from the University of Brasília and a PhD from Oregon State University.
Ieda Mendes, Embrapa Cerrados
AgriBrasilis – What does soil bioanalysis (SoilBio) consist of?
Ieda C. Mendes – Until July 2020, when a farmer sent a soil sample for laboratory analysis, they could only access the chemical aspects (acidity components, macro and micronutrients) and some physical aspects of the soil (largely determinations of clay, silt, and sand content). A major gap existed in these analyses, specifically the absence of a biological component. And biology is the basis of soil health. The more biology, the healthier the soil. The less biology, the sicker the soil.
Launched in July 2020, SoilBio is a technology developed by Embrapa that adds the biological component to traditional routine chemical analyses of soils (pH, H+Al, P, Ca, K, Mg, etc.). It consists of analyzing the enzymes arylsulfatase and β-glycosidase, associated with the sulfur and carbon cycles, respectively, and fills the gap left by the absence of the biological component in soil analyses.
It is like a “blood test” for the soil, allowing asymptomatic soil health problems to be anticipated earlier, before they lead to crop productivity losses.
SoilBio allows farmers to monitor the health of their soil, knowing exactly what to evaluate (arilsulfatase and β-glycosidase enzymes), how to evaluate (soil collected at a depth of 0 cm–10 cm), when to evaluate (after harvesting crops), and how to interpret what has been evaluated (via reference values that allow us to assess, for each soil type, whether the level of enzyme activity is low, medium, or adequate).
Today, we have a lot of research data proving that healthy soils are biologically active, productive, and resilient, better tolerate problems caused by lack of rain, promote the health of plants, people, and animals, and preserve environmental quality, providing, among other benefits, carbon sequestration, water storage and infiltration, bioremediation of pesticides, and mitigation of greenhouse gas emissions.
AgriBrasilis – How does this method differ from others?
Ieda C. Mendes – Leonardo da Vinci’s famous quote — “Simplicity is the ultimate sophistication” — captures the spirit of SoilBio. Although it assesses something complex — soil health — it was developed to be practical, accessible, and easy to understand. With a single sample collected at the right time and depth, farmers can assess the biological functioning of their soil, going beyond traditional chemical analyses. By enabling soil health assessment, SoilBio technology provides input for management decisions aimed at maintaining productive and sustainable crops in healthy soils. It’s a win-win process for everyone: farmers, society, the environment, and, of course, our planet.
AgriBrasilis – Can SoilBio replace chemical analysis?
Ieda C. Mendes – SoilBio and chemical soil analysis complement each other. Without the correct chemical balance, crops will not develop, especially in the acidic and low-fertility soils of the Brazilian Cerrado. However, the soil may often be in excellent chemical condition but compromised from a biological point of view. This compromise not only affects crop productivity but also makes the soil less resilient. In other words, it becomes more vulnerable, for example, to problems caused by a lack of rain.
SoilBio has been available to farmers since July 2020. The cost of a complete SoilBio (involving enzymes, organic matter, routine soil chemistry analysis, and granulometry) varies between US$ 29.30 to US# 38.47.
“All healthy soil is productive, but not all productive soil is healthy…”
AgriBrasilis – Why are the enzymes evaluated considered a “soil fingerprint”?
Ieda C. Mendes – Different management systems leave distinct “fingerprints” on the soil, such as mechanical tillage operations or the quality, quantity, and frequency with which plant residues are added to the soil. Knowing how to access this “memory” of the soil was a complex problem that required a simple solution.
The soil’s ability to store in its “memory” the type of management to which it has been subjected is closely related to its living part, its biological component. Thus, over two decades of studies, in addition to aspects related to soil health, it was found that the soil’s ability to store information about the type of management to which it was subjected could be accessed by determining the enzymes SoilBio, arylsulfatase, and β-glycosidase.
Enzymatic activity represents the total enzymes that are active in the soil, coming from: i) Living organisms that are active at that moment (fungi, bacteria, roots, earthworms), ii) Remnants of organisms that have already passed through the soil, whose enzymes remained stored there. Some of these enzymes may remain present in the soil even after the death of these organisms because they bind to clay particles and organic matter, remaining protected for a long time. Therefore, the soil can store information about its history of use, as if it were a biological archive, and enzymes can be used to access this “soil memory.”
AgriBrasilis – What is the impact of SoilBio on crop productivity?
Ieda C. Mendes – All healthy soil is productive, but not all productive soil is healthy. High productivity, corrected pH, or adequate nutrient levels do not always mean that the soil is healthy. We need to look beyond that.
Results from several technical and scientific studies indicate that, on average, soybean productivity in areas with healthy or recovering soils ranges from 520 to 680 kg ha⁻¹ higher than that obtained in areas with diseased or unhealthy soils, reinforcing the relationship between soil health and high yields in high-quality production environments.
But again, it is important to remember that soil health goes far beyond crop productivity. Healthy soils are biologically active soils, capable of storing water and with high potential for nutrient cycling, carbon sequestration, and pesticide bioremediation.
Just as companies invest in the health of their workers to improve their performance, investing in soil health also brings returns: higher productivity, greater efficiency in the use of water and fertilizers, more resilient soils, and better ability to degrade pesticides. In other words, those who take care of the soil reap better results, both financially and environmentally.
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